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The volunteer – let us call him Patient A – was alert and focused as the experiment began. He was a doctor, somewhere near the peak of his powers, and right-handed. But being alert is not the same as being able to see. Less than six months before the experiment, then aged 52, he had suffered a stroke. Within 36 days, another seizure silently tore through his brain. The effect was disastrous.

The first stroke destroyed the principal visual areas on the left of the brain; the second did the same on the right, devastating the right occipital lobe and wiping out his remaining visual field. Consequently, regrettably, inevitably, he was blind.

The stroke damage to his visual cortex was so severe that he was unable to detect colours, or movement, or a low spotlight beam shone directly into his eyes. If you showed him pictures of shapes – triangles or a bunch of circles, even 200 of them – no matter how big or small, he had no way of distinguishing between them. For all intents and purposes, as Milton wrote about his own blindness, his ‘light was spent’. Regrettably, inevitably, given the severity of the strokes. But his complete cortical blindness was not the end of the story. There was something else, something that puzzled his doctor Alan Pegna.

Pegna is a gloriously affable man with the soft, comforting contours of his face matching his soothing voice. He has boundless enthusiasm – precisely the kind of person you’d want as your clinician. When he speaks his ideas and interests pour out, drawing you in, uplifting the listener. And that is what is so unusual about what happened with Patient A, because on the day it happened Pegna was being uncharacteristically quiet. Pegna thinks deeply about the brain and has cutting-edge ideas about what it is – about what we are.

‘As a teenager, I dreamed of asking questions that no one at the time was much asking. I became interested in the intersection of biology and philosophy, how the brain can determine how we see the world and what it means to us. It remains astonishing to me.’

And it still astonishes Pegna that one day, out of the blue, the physical evidence pointing to one of the most profound discoveries in his research career was there, right in front of his eyes.

‘That day I walked into the consulting room to see this patient as normal. Nothing unusual, but I was thinking – about something – and instead of saying hello I smiled and nodded. And that was what was amazing. My patient nodded and smiled back. He nodded as I’d nodded, he returned my smile a fraction of a second after my smile, and yet he was blind. I said to him, “Why did you do that? How could you do that?” He said he didn’t know what I was talking about. I said that he returned my smile and he must be improving, because he must have seen me. He said that he had no idea what I was talking about. He said, “I’m in total darkness.” And yet, I was thinking, how could he do that? How could he return my smile? How could he “see”?’

There is a long and remarkable history of scientific serendipity – the happy occurrence of events. In 1928 Alexander Fleming was cultivating the bacterium Staphylococcus aureus as part of his study of influenza. He left for his holiday in August, but when he returned to St Mary’s Hospital, Paddington in September, he noticed the growth of an unwanted mould in his Petri dishes. ‘That’s funny,’ he immortally said. For bizarrely enough, the bacteria around the mould had died. The uninvited fungal intruder had killed them. He had discovered penicillin.

In 1964 Robert Wilson and Arno Penzias were using a type of radio telescope to scan the skies from Holmdel, New Jersey, when there was an annoying background buzzing, an incessant interference they just couldn’t get rid of whatever they did. But the buzzing wasn’t a system fault – it was the system itself. The buzzing was the cosmic microwave background, thermal radiation blown across time and space by the birth of the universe. The buzzing was the remnants of the Big Bang.

And just after the millennium, Dr Alan Pegna was checking on one of his clinical patients who was cortically – thus for all intents and purposes totally – blind, when something serendipitous happened, when he had his own ‘That’s funny’ moment. Pegna slowly realised that his patient could somehow ‘see’ the smile on his face.

Being a researcher as well as a clinician, Pegna immediately resolved to test the curious phenomenon. For the circles of serendipity worked in another way also: a complex chain of coincidental events that led to Patient A being in the examining room in Geneva of a doctor who was also neurological research frontiersman.

When Pegna began his research into the links between anatomy and emotion, he was told by supervisors that emotions can’t be measured, are too subjective – it wasn’t really science. But Pegna didn’t give up. Time (and technology) has proved his hunch right.

Patient A hails from the Republic of Burundi, in the Great Lakes region of Central Africa. He was a physician working for the World Health Organisation in Chad. It was in Chad that he suffered a severe stroke. Because he happened to be working for the UN’s coordinating health authority at that moment, he was flown to Geneva for treatment.

But the nature of the remarkable condition Patient A possesses would not have come to light if he had not suffered a second stroke. Coincidentally, it was in virtually the same brain region as the first, but on exactly the opposite side. I say coincidentally advisedly, since this degree of symmetry in damage is really rather rare. Nevertheless the bilateral damage resulted in total cortical blindness. But at the same time there was – serendipitously – a vital part of his brain that remained intact and fully functioning. And that was to change everything.

And finally, when he unconsciously mirrored the smile of his clinician in Geneva’s University Hospital, the man standing before him was Dr Alan Pegna, who was not only a doctor but a researcher intensely concerned with exploring the secret pathways of the human brain. This catalogue of contingencies is how science sometimes works.

‘I am in total darkness,’ Patient A told Pegna. ‘I can’t see you. But for some reason, I was under the impression you were smiling.’

How could a blind person form such an impression? For ‘some’ reason? What reason?




About the Perceiver of Pain: here.

Where to get the book: here.